Giuseppe Pappagallo, Antonio Leone, Antonio Lo
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Use of SWAT model for evaluation of anthropic impact on water resources quality and quantity in Celone Creek Basin (Apulia – ITALY) Giuseppe Pappagallo, Antonio Lo Porto Water Research Institute – National Research Council (IRSA – CNR), Bari (ITALY) Antonio Leone Environment and Forests Technologies Engineering and Sciences Department (DAF) Tuscia University, Viterbo (ITALY) PURPOSE 1) Analysis: -WATER QUALITY (Sediment Yield; N – P Losses) - HYDROLOGICAL BALANCE in CELONE Creek Basin (S. Giuliano Reservoir – 25 millions m³) in N-W Apulia area at “HIGH DESERTIFICATION RISK” 2) Planning of Best Management Practices (BMP) : structural type ( i. e. buffer zones) and managerial type (inputs abatement). Ischitella Peschici Chieuti Lesina Cagnano Varano Vieste Poggio Imperiale Carpino Serracapriola Apricena Mattinata S.Paolo di Civitate Monte S.Angelo Torremaggiore S.Marco in Lamis S.Giovanni Rotondo S.Severo Carlantino N Celenza Valfortore W E Manfredonia Volturino Lucera S Foggia Zapponeta Biccari Troia Roseto Valfortore Carapelle Trinitapoli Ortanova Cerignola Orsara di Puglia Barletta Ordona Bovino Deliceto Canosa Panni Ascoli Satriano RAINFALL TREND (78-94) TEMPERATURE TREND (78-94) Mixt. of agricultural and nat. areas Urban Water Mixt. of herbaceous and tree crops Herbaceous crops (spring-summer) Horticulture (summer/fall/spring) Horticulture (spring/summer) Fruit trees (irrig.) Olive groves (irrig.) Olive groves (not irrig.) Pasture Arable land (not irrig.) Complex systems Vineyards Forests LAND USE/SOIL TYPE NITROGEN LOAD by HRU NO3 in percolation Riv7.shp Perc NO3 (kg/ha) 0 - 10.44 10.44 - 20.87 20.87 - 31.31 31.31 - 41.75 41.75 - 52.19 N W E 8 0 8 16 Kilometers S PHOSPHORUS LOAD by HRU Sediment P Riv7.shp Sediment P (kg/ha) 0 - 0.94 0.94 - 1.88 1.88 - 2.82 2.82 - 3.76 3.76 - 4.7 N W E 8 0 8 16 Kilometers S EROSION (t) 255 1,927 FRSD OLIV PAST 14,758 TOMA WWHT 23,808 12,950 EROSION (t/ha) 2.39 2.32 3.48 PAST OLIV TOMA 9.55 FRSD WWHT 51.85 SEDIMENT Sediment Yield (t) 0 - 12.35 12.35 - 24.69 24.69 - 37.04 37.04 - 49.38 49.38 - 61.73 N W E 8 0 8 16 Kilometers S MIN LOSSES (HRU); NUTRIENT MAX LOSSES (HRU); LOAD LOAD Organic N W W Tomato/Clay W W Tomato/Silt-Clay Pasture/Fine Sand N in W W Tomato/Silt-Clay subsurface flow Pasture/Fine Sand N in runoff W W Tomato/Clay-Loam Forest/Sand NO3 Forest/Fine Sand W W Tomato/Silt-Clay in percolation Forest/Sand Insoluble P W W Tomato/Clay Pasture/Fine Sand Forest/Sand Soluble P W W Tomato/Clay-Loam Pasture/Fine Sand WATER BALANCE (mm) 150 mm 140 et perc 120 ret.flow lat.flow 100 runoff 100 mm prec 80 60 40 20 0 1 2 3 4 5 6 7 8 9 10 11 12 et 19.24 23.47 40.09 77.53 109.1 48.79 119.04 40.84 28.36 20.47 15.81 14.22 perc 59.77 50.72 0.06 5.39 0.22 0 0 0 0.15 1.46 2.14 5.28 ret.flow 8.52 10.96 13.82 12.89 11.75 8.79 7.38 6.24 5.47 5.21 4.51 4.32 lat.flow 5.36 3.64 1.3 1.26 0.7 0.36 0.45 0.21 0.24 0.75 1.17 0.96 runoff 22.42 21.88 0.02 3.23 2.11 0.28 0.23 0.01 11.67 15.76 0.97 5.78 prec 102.54 95.14 60.89 56.45 36.8 56.14 30.4 16.49 33.43 58.84 22.85 47.34 WINTER WHEAT TOMATO CROP SEQUENCE DATA 11,000 ha Area (75.4 %) Groundwater Recharge 8,243,000 m3 Irrigation (ground- water withdraw) 35,000,000 m3 Recharge/Withdraw 25 % Annual Deficit 26,757,000 m3 Groundwater 12 m / 48 years Drawdown (1 m / 4 years) CONCLUSIONS 1 - Sediments are not a real danger for the study area. The greatest contribution to sediment yield is given by subbasins occupied by tree crops (olive groves) that yet have a modest extension compared with basin area. These areas therefore could be protected simply respecting the agricultural “best management practices” and undertaking soil and water conservation works. 2 - Actual land management doesn't represent a risk factor concerning nutrients mobilization. In fact, where agricultural activities are more intensive there is a regulated fertilization use, while in areas characterized by less human activity the nitrogen and phosphorus concentrations respect normal loads released by normal transformation processes of organic matter. CONCLUSIONS 3 - The most important problem emerged by results analysis is the water deficit caused by the huge groundwater withdraw (not always authorized). These are almost exclusively destined to winter wheat/tomato crop sequence, for which irrigations are essential in summer months, when however there are high temperatures, few precipitations and maximum evapotranspiration. 4 - The research showed that aquifer recharge areas coincide with forests which assume therefore great importance to save groundwater resources quantity. To valorize such role forests management should not only be devoted to normal productive finalities, but also, and above all, to preserve landscape, improving the soil water absorption capability, increasing effective infiltration. CONCLUSIONS 5 - The analysis underlines current land use irrationality (winter wheat/tomato alternation) which cannot be sustained longer. Groundwater abuse, in effect, on one hand is slackening the artificial reservoir filling, making vain its building costs (economic and environmental); on the other it can damage aquatic ecosystems, since the water quantity is lesser than the minimum flow requisite for flora and fauna survival in freshwater. Uncontrolled withdrawals are determining the consistent groundwater drawdown observed in last years. 6 - From simulation results emerges the satisfying reliability of SWAT outputs that is expected to become higher as soon as more frequent (in space and time) measured values are available (ongoing projects). That confirms the model utility, together to the GIS technology, both in the evaluation of land use impact (referring particularly to diffuse pollution) and, in general terms, in the territory study and management. Thanks to these tools, in fact, it is possible not only to define damage type and entity, but also to locate its exact position in examined area. In this way it is possible to realize rehabilitation works that will have a greater effectiveness and will be economically more rational. The End NITROGEN BY HRU (Kg/ha) PHOSPHORUS BY HRU (Kg/ha) SEDIMENT (t/ha) 60.00 SOLP kg/ha SEDP kg/ha SYLD t/ha 50.00 40.00 30.00 20.00 10.00 0.00 FRSD / FRSD / FRSD / PAST / TOMA / TOMA / WWHT / WWHT / WWHT / WWHT / WWHT / WWHT / WWHT / WWHT / OLIV / clay clay sand vfsand vfsand siltclay vfsand clay clayloa loam sand sicloam siltclay sncloam vfsand SOLP kg/ha 0.12 0.01 0.00 0.11 0.03 0.21 0.08 0.04 0.09 0.08 0.02 0.04 0.03 0.09 0.01 SEDP kg/ha 1.01 0.94 0.86 3.26 1.03 0.88 4.70 1.41 1.02 1.78 0.73 0.65 0.72 2.09 1.31 SYLD t/ha 18.52 2.98 1.41 51.85 2.32 0.70 18.40 4.37 1.34 3.00 1.74 0.89 1.79 3.88 9.97 SEDIMENT YIELD Migliaia 25 SEDP kg 20 ORGN kg SYLD t 15 10 5 0 TOMA WWHT WWHT WWHT WWHT FRSD / FRSD / FRSD / OLIV / PAST / TOMA WWHT WWHT WWHT WWHT / / / / / clay sand vfsand clay vfsand / vfsand / clay / loam / sand / vfsand siltclay clayloa sicloam siltclay sncloam SEDP kg 497 110 2.146 995 116 188 454 2.467 2.085 2.002 707 1.300 884 1.980 316 ORGN kg 3.735 883 11.478 8.283 723 588 2.088 13.672 10.024 11.153 3.875 6.229 3.786 10.803 1.975 SYLD t 9.169 374 3.407 14.758 255 149 1.778 6.700 2.549 3.725 1.366 1.636 1.559 3.857 2.416.